306 THE BEGOLTTH 



well-known Bog of Allen, made in county Kildare, is given 



below.^ 



Thickness 



(1) Dark reddisli brown; mass compact j no fibres of moss visible; 



surface decomposed by atmosphere 2 feet 



(2) Light reddish brown; fibres of moss very perfect 3 



(3) Pale yellowish brown; fibres of moss very perceptible ... 5 



(4) Deep reddish brown; fibres of moss perceptible . , , . 8i feet 



(5) Blackish brown; fibres of moss scarcely perceptible, contains 



numerous twigs and small branches of birch, elder, and fir . 3 



(6) Dull yellow-brown; fibres not visible; contains much empyreu- 



matic oil; mass compact 3 



(7) Blackish brown; mass compact; fibres not visible; contains 



much empyreumatic oil 10 



(8) Black mass, very compact; has a strong resemblance to pitch 



or coal; fracture eonchoidal in all directions; lustre shining . 4 



Total depth of bog 38^ feet 



Underlaid by 3 feet of marl containing 64% carbonate of lime, 4 feet of 

 blue clay, and this in its turn by clay mixed with limestone gravel of an 

 unknown thickness. 



IT. Bupert Jones, Proe. of the Geologists' Association, London, Vol. YI, 

 No. 5, January, 1880. This authority classifies the peat bogs, swamps, and 

 marshes, as follows: — 



L Peat bogs and turf moors on such plateaux as flat mountain tops and 

 wide hill moors. 



II. Peat bogs of valleys: (1) At the heads of valleys; (2) at the salient 

 angles within river curves; (3) in deserted beds of rivers; (4) in plains 

 and lakes of expanded valleys; (5) special peat bogs of Denmark and the 

 black earth of Russia; (6) river deltas; (7) maritime peat marshes, where 

 certain valleys and plains open to the sea. 



Regarding the black earth of Russia, it should be stated that this is now 

 regarded by at least one authority (Hume, GeoL Mag., Vol. I, No. 2, 1894) 

 as being but a local phase of the loess, the color being due to the preva- 

 lence of organic matter. 



Shaler (Ann. Rep. XJ. S. Geol. Survey, 1888-89), on a basis of physical 

 characters, classifies the inundated lands of the United States as below: — 



,, . , fAbove mean tide . . / G^rass marshes. 



Marine marshes ^ \ Mangrove marshes. 



^ Below mean tide . . / Mud banks. 



\ Eel-grass areas. 



Fresh-water swamps 



"River swamps • . ./Terrace. 



\ Estuarine. 

 Lake swamps . . . / Lake margins. 



\ Quaking bogs. 

 Upland swamps . . / Wet woods. 



\ Climbing bogs. 

 ^Ablation swamps. 



